Effect of the Heating/Cooling Rate of Nonisothermal Aging on Microstructure and Mechanical Properties of 2050 Al–Li Alloy

Abstract

The effect of the heating/cooling rate of non‐isothermal aging (NIA) on microstructure and mechanical properties of 2050 Al‐Li alloy were investigated. The 2050 Al‐Li alloy was first solid‐solutioned and pre‐deformation, and then heated from 130 °C to 220 °C at different rate of 20 °C/h, 30 °C/h or 40 °C/h and then cooled to 150 °C. The results show that the mechanical properties of the alloy subjected to NIA treatment could be improved by adjusting the heating and cooling rate. When the heating and cooling rate was 30 °C/h, the alloy achieved the best mechanical properties, the hardness, ultimate tensile strength (UTS), yield strength (YS), and elongation were 182.9 HV, 597 MPa, 571 MPa, and 9.6%, respectively. With the decrease of heating (or cooling) rate of NIA, the diameter and thickness of the T1 precipitate increased and the volume fraction decreased, resulting in the variation in mechanical properties. Therefore, in the present study, premier precipitation behavior and improved mechanical properties was both achieved by modifying the heating and cooling rate of NIA, the effect of the heating/cooling rate of NIA on the microstructure evolution of 2050 Al‐Li alloy was revealed, the underlying strengthening mechanism was investigated in detail.This article is protected by copyright. All rights reserved.